Tile Calculator

Tile Calculator works out how many tiles a floor or wall needs and converts that into boxes, which is what you actually buy. It accounts for the grout gap, which makes each tile occupy slightly more area than its own size, and for a waste allowance to cover cuts and breakages.

Ten per cent waste is the standard allowance and is enough for a simple rectangular room laid square. Fifteen per cent is more realistic for a diagonal layout, a room with alcoves or anything with a lot of edge cuts, since every cut tile leaves an offcut that usually cannot be used elsewhere.

The spare count is shown deliberately. Buy from one batch: tile colour varies between production runs, so a box bought a year later to replace a cracked tile will not match the rest of the floor. Keeping the leftovers from the original order is the only reliable way to have matching spares.

The page shows its working, not just its answer. Where there is a formula it is printed with your own numbers substituted in, so you can check the result rather than take it on trust -- which is the difference between a calculator you can use for something that matters and one you cannot.

Everything runs inside your browser. What you type is never uploaded, never logged and never stored, and the calculator keeps working if your connection drops after the page has loaded.

• Shows tiles needed, boxes to buy, area to tile, spare tiles and cost together, so you are not running it twice
• A results table you can read across
• Updates as you type, with no button to press and no page reload
• Copy the result in one click
• Free, no sign-up, and it runs entirely in your browser

The tile calculator is used by writers, developers, students, marketers and anyone else who needs the job done once without installing software. Common cases include:

• Working out tiles and boxes for a bathroom or kitchen floor
• Allowing for extra waste on a diagonal layout
• Excluding the area under fitted units
• Comparing the cost of two tile sizes